Facebook and Vevo are the latest companies to cancel their plans to attend SXSW over mounting coronavirus concerns, even as festival organizers say the event will go on.

On Monday night, announcements came in rapid succession as social network giant Facebook and then Vevo, the music video streaming company, announced they would no longer send any employees to SXSW, the tech, music and film festival in Austin, Texas, slated for March 13-22.

"Due to concerns related to coronavirus, our company and employees will not be participating in SXSW this year," a Facebook spokeswoman said in an e-mail statement.

In a statement to Ad Age, Vevo became the most high-profile music entertainment brand to announce its departure from the festival lineup. "After careful consideration of all known and unknowns regarding the coronavirus," a Vevo spokesman said in the statement, "Vevo has decided to cancel its annual SXSW event this year. We'd like to thank our partners for their support and understanding. We hope to see you next year."

Vevo—the joint-venture video hosting service backed major labels Universal Music Group, Sony Music Entertainment and EMI—had planned to showcase musical acts as it does every year.

Coronavirus, officially known as COVID-19, has been disrupting business and travel since January after an outbreak originated in China. The virus has so far claimed six lives in the U.S., and health officials expect it to spread further. The virus carries flu-like symptoms and is considered to have a fatality rate of around 2 percent.

Austin and SXSW officials have been monitoring health warnings for weeks. "At this time, no health departments in the state have requested the cancellation of any gatherings as the current risk of person-to-person spread in their jurisdictions remains low," SXSW officials said on Monday.

Companies that are still planning to attend have been in touch with SXSW organizers regularly, receiving updates about plans for health and safety, according to one executive going to the event, who spoke on condition of anonymity because talks with the festival organizers were not public. The executive said SXSW organizers were communicating with companies as recently as Monday night to prepare extra health precautions for visitors.

Still, on Sunday night Twitter announced that it canceled its SXSW house and CEO Jack Dorsey would no longer attend for a prominent speaking slot that had been scheduled. And yet, on Monday new names were added to the list of speakers: Former Secretary of State Hillary Rodham Clinton said she would partake in a talk with MSNBC host Joy Reid.

Austin officials are also feeling the pressure to reconsider hosting SXSW at all as a change.org petition started picking up support over canceling the event. By Monday, it garnered more than 25,000 online signatures.

Representatives from Snapchat and Reddit said as recently as Monday afternoon that they are holding strong with plans to attend SXSW. Jen Wong, Reddit's chief operating officer, is among the list of high-profile SXSW speakers.

TikTok, the Chinese-based social video app, is also expected to send staff to SXSW. However, people familiar with TikTok's plans say the company is rethinking its attendance, too, as of Monday night. TikTok was not immediately available for comment on its plans, however.

Companies have been rethinking travel for weeks. Last month, Mobile World Congress was canceled in Barcelona, and just this weekend the Geneva Auto Show was canceled. Last week, Facebook announced it would not host F8, its yearly developer conference, which was supposed to run in May. Meanwhile, companies like Amazon and WarnerMedia issued notices that they would restrict employee travel to only the most essential trips.

On Monday, Adobe also canceled its yearly developer event, which was set for Las Vegas later this month. All signs pointed to more companies canceling similar outings as the U.S. takes stock of the spread of the sickness and as more cases continue to be reported.